The fourth quadrant set of quadrant angle s = {α | - 90 ° + K · 360 ° If the former does not work, what is the specific meaning of | 2K π + 3 π / 2 ＜ α＜ 2K π + 2 π, K ∈ Z}? The meaning of K and the origin of π are not clear.

RELATED INFORMATIONS

• 1. Why is it that {α | α = 120 ° + (2k + 1) · 360 ° K belongs to Z} is not 120 ° at the end edge?
• 2. If X1 and X2 are the two real roots of the equation x ^ 2 - (2k + 1) x + K ^ 2 + 1 = 0 about X, and X1 and X2 are greater than 1
• 3. The square of K x + (2k + 1) K + K-2 = 0 is the square of x 1 + x 2 + x 2 = 3 Notice that K times the square of X
• 4. If the sum of the four numbers of the arithmetic sequence is 52, and the product of the second number and the third number is 160, then the four numbers are in turn RT
• 5. From 1, 2, 3 Any three different numbers in the 20 numbers, 20, are used to form the arithmetic sequence________ Let a, B, C be equal difference, ∵ 2B = a + C, we can know that B is determined by a, C, and ∵ 2b is even number, ∵ a, C are the same odd or even, that is, from 1,3,5 , 19 or 2,4,6,8 In this way, we can determine the arithmetic sequence, C (2,10) * 2 * P (2,2)?
• 6. Is the tolerance of arithmetic sequence 2n, 2m I mean, for example, a function minus another function to get a number like 2n 2m, ask if it's an arithmetic sequence, thank you
• 7. In the sequence {an}, A1 = 0, and for any k ∈ n, a2k-1, a2k, a2k + 1, the tolerance is 2K 0 - 13 days and 2 hours to the end of the problem In the sequence {an}, A1 = 0, and for any k ∈ n, a2k-1, a2k, a2k + 1, the tolerance is 2K. (1) prove that A4, A5, A6 are equal proportion sequence; (2) find the general formula of the sequence {an}. (3) note TN = 2 & sup2 / / A2 + 3 & sup2 / / A3 + +N & sup2 / an proof (3 / 2 < 2n-tn2)
• 8. It is known that {an} is an arithmetic sequence, tolerance D ≠ 0, an ≠ 0 (n ∈ n +), and a (k) x ^ 2 + 2A (K + 1) x + a (K + 2) = 0 (K ∈ n +) (1) Proof: when k takes different natural numbers, the equation has a common root (2) If the roots of different equations are x1, X2 ,Xn,… To prove the sequence 1 / (x1 + 1), 1 / (x2 + 1) ,1/(Xn+1)… Is an arithmetic sequence
• 9. If the sum of the first k terms of the arithmetic sequence {an} is 30 and the sum of the first 2K terms is 100, then the sum of the first 3K terms of the arithmetic sequence {an} is?
• 10. It is known that sequence {an} is an arithmetic sequence, CN = an ^ 2-A (n + 1) ^ 2 (n belongs to n *) If a1 + a3 +... + A9 = 30, A2 + A4 +... + A10 = 35-5k (k is a constant), try to write the general term formula of the sequence {CN};
• 11. 92 π / 7 is reduced to a + 2K π (0
• 12. Selection: among the following groups of numbers, only the two numbers with common factor 1 are (). ① 13 and 91 ② 26 and 18 ③ 9 and 85 ④ 11 and 22 The number that is divided by 3, 5 and 7 to make 2 ① It must be 105, it must be 107, it must be 37, it must be countless
• 13. Among the following groups of numbers, only the two numbers with the common factor 1 are () A. 13 and 91b. 26 and 18C. 9 and 85
• 14. 6cos(2kπ+π/3)-2sin(2kπ+π/6)+3tan(2kπ) k€Z
• 15. Given the set P = (a = 2K Π + 5 / 6 Π, K ∈ z), the set Q = (b = 2K Π - Π / 6, K ∈ z), then which set does the angle-7 / 6 Π belong to?
• 16. If the set a = {α | π / 3 + 2K π
• 17. If Tan x is greater than Tan Π / 5 and X is in the third quadrant, the value range of X is obtained RT, just learn not very clear ==
• 18. When TaNx > 0, the value range of X is?
• 19. The value range of X when TaNx = 0
• 20. If TaNx > Tan π / 5 and X is the third quadrant angle, then the value range of X is